INS 509 is calcium chloride, numbered E509 in Europe. It is a white salt that dissolves very readily in water and has a salty, slightly bitter taste. It is obtained from natural brines, as a by-product of soda ash production, or by reacting limestone with hydrochloric acid. Codex lists it as a firming agent, stabilizer and thickener.
Its main job is firming. Calcium ions link with pectin in plant cell walls and with some proteins and gums, so calcium chloride keeps canned vegetables and fruit pieces firm, helps milk coagulate in cheese making, and is one of the coagulants used for tofu.
On SeekSnack, Lay’s Play 3D Cheese Pizza lists it as a firming agent, and it is among the food additives in Fashion Food Paprika Flavoured Cracker and its tomato counterpart.
